1. Field of the Invention
This invention relates to the providing of fire resistant seals for building construction. It is particularly concerned with the sealing around pipes and other members passing through fire resistant walls and floors.
2. Prior Art
In the construction of residential and commercial buildings it is often necessary that pipes and other members such as electric cables, electric cable trays and telephone cable trays pass through walls, floors and ceilings. The holes for these members are necessarily somewhat larger than the members themselves. Therefore, in the event of fire, it is possible for flames, heat and smoke to pass around these pipes and other members thereby spreading damage and fire. The desirability of sealing around these openings is particularly important in the instance of fireproof walls. Without sealing around openings through these walls, the safety and fire protection which is their purpose is lessened.
It has been known to inject a silicone foam around pipes where they pass through fireproof partitions. However, this material is very expensive and further if utilized in a ceiling requires the sealing of the opening with something to prevent its running out prior to hardening. A method of sealing to prevent run-out is to press a fiberboard against the opening for several minutes until the material hardens. Another disadvantage of silicone foam even when combined with fibers is that it requires special equipment for mixing and must be used within about two minutes of formation or it will harden and not be usable.
Another method of attempting to seal where members pass through fiberproof partitions is to stuff fiberglass or ceramic fibers around the pipe in an attempt to prevent the passage of flames, smoke and gases. However, this is difficult as the material does not stick well in holes in ceilings and floors and is easily dislodged even when utilized in walls. The material further is not gas- or smoke-impermeable to a great extent.
Therefore, there is a continuing need for an improved method of sealing around pipes and other members which pass through partitions in buildings in order to improve their fire resistance.